The Oregon Department of Geology and Mineral Industries (ODOGAMI) has issued a landslide advisory for the region.
The advisory follows the National Weather Service's (NWS) Flood Watch posted earlier today. The NWS is forecasting a prolonged period of rain through Wednesday morning. Four to eight inches of rain is expected across the higher terrain with around two inches for the interior valleys.
The rain will be heavy at times, and there could be locally higher rain totals. Snow levels will be above 6000 feet, and snow melt may contribute to excessive run off.
Heavy rain can trigger landslides, rock fall, and debris flows in steep terrain, and the risk is higher in burn areas, according to ODOGAMI.
Find the latest information at https://alerts.weather.gov/cap/or.php?x=1
ODOGAMI said debris flows are rapidly moving, extremely destructive landslides. They can contain boulders and logs transported in a fast-moving soil and water slurry down steep hillsides and through narrow canyons. They can easily travel a mile or more. A debris flow moves faster than a person can run. People, structures and roads located below steep slopes in canyons and near the mouths of canyons may be at serious risk.
If your home, work, or route is in a watch area:
Stay alert. Track the flood watch by radio, TV, weather radio or online. If told to evacuate, do so immediately.
- Listen. Unusual sounds might indicate moving debris, such as trees cracking or boulders knocking together. A trickle of falling mud or debris may precede larger landslides. If you think there is danger of a landslide, leave immediately.
- Watch the water. If water in a stream or creek suddenly turns muddy or the amount of water flowing suddenly decreases or increases, this is a warning that the flow has been affected upstream. You should immediately leave the area because a debris flow may soon be coming downstream.
- Travel with extreme caution Assume roads are not safe. Be alert when driving, especially at night. Embankments along roadsides may fail, sending rock and debris onto the road.
A landslide closed Highway 30 three miles east of Astoria for a time last week. Crews were able to remove the rocks, mud and other debris and reopen the highway by late Friday, Jan. 8.
The Oregon Department of Transportation's Lou Torres said the highway slide was caused by excessive rainfall and unstable soils.
Torres said drivers need to keep both hands on the steering wheel, mind on driving and eliminate distractions.
"Be prepared for winter driving conditions which can mean dealing with wet and icy roads, snow, high water and possibly rock and mud slides," Torres said.
For more landslide and debris flow information, visit https://www.oregongeology.org/Landslide/debrisflow.htm